Method of making brake shoes



Sept. 4, 1934. s. WHITWORTH 1,972,212

METHOD OF MAKING BRAKE SHOES Filed March 5, 1930 mmvroz sTlplLEYWHITWORTH A TTORNEY Patented Sept. 4, 1934 "PATENT OFFICE- METHOD OFMAKING BRAKE SHOES Stanley Whitworth, South Bend, Ind., assignor toBendix Brake Company, South Bend, Ind., a

corporation of Illinois Application March 5, 1930, Serial No. 433,201

Claim.

This invention relates to brakes in general and more particularly to amethod of fabricating the most essential part of an internal expandingautomotive brake, namely, the friction element 5 thereof.

Heretofore, the manufacture of both the band and shoe elements of thistype of brake has been effected by any one of several processes, such asdie casting or welding, which processes can be improved upon bysimplification with a consequent cost reduction.

To the end, therefore, that the production of the friction element besimplified. there is sug-,

gested the process elaborated in more detail below, preferablycomprising the shaping, by either a hot or cold rolling process, ofsuitably dimensioned and sectioned stock into a helix or spiral form andsubsequently cutting, from the helix so formed, either brake shoesegments or annular 2o band brake segments as desired. The segments maythen be straightened, perforated and otherwise shaped to effect thefinished product.

Further details and novel features of the invention will become'apparentfrom the following detailed description of a preferred mode ofpracticing my invention exemplified in the .drawing forming a part ofthis specification, in which:

Figure 1 is a view partly in elevation and partly. in section showing aT- section type of stock rolled to the helix form;

Figure 2 discloses a brake shoe member in its final state, the samehaving been cut as a segment from-the helix of Figure 1; and

Figure 3 discloses a band or annular type of friction element employedin internal expanding brakes which may also be cut from the stock ofFigure 1.

In practicing the preferred embodiment of my invention, I suggest firstthat a straight length 40 of relatively narrow gauge flat sheet steelstock be folded to provide a double thickness rim and web of T shape incross section. The straight length of this T section stock so folded maythen be sufliciently heated to render the same pliable, and bent into acoil or helix, as shown in Figure 1. From this stock, which is readilyportable and also readily packed and stored, the segments necessary toeffect the brake shoe of Figure 2 or the hand brake element of Figure 3are cut. To finally form the brake shoe product of Figure 2, it isnecessary to straighten the stock so that the web portion 10 thereoflies in a single plane. The web portion may also be cut awayintermediate the ends of the shoe to provide reinforcing or .as byriveting.

thickened end and intermediate portions 12 and 14, respectively.

The web portion may also be provided with suitable openings at theaforementioned reinforced portions to accommodate certain of the m usualremaining elements of the brake assembly with which it co-operates. Therim 16 of the shoe segment may also be provided with the conventionalbrake lining 18, rigidly secured thereto I From the same diameteredstock of Figure 1, the continuous or annular band friction element ofFigure 3 may be formed, the web of which may subsequently be cutawayintermediate its ends to provide the tapered web portions 20 to increasethe flexibility of the band. I prefer that all of the web be deletedthroughout a substantial sector of the centerof the band. The ends ofthe rim of the band may'also be turned inwardly friction elements by anextremely simple sequence of operations. While I have described apreferred mode of practicing my invention, it is to be understood thatthe same is merely an examplification of many possible ways of carryingout the same and it is to be understood that the invention is limitedonly by the scope of the appended claims.

I claim:

1. That method of fabricating a brake friction element or the likecomprising forming a flat length of formable metal into twosubstantially perpendicular flanges rolling the thus sectioned stockinto a helix, cutting to length, from said helix-shaped stock,discontinuous cylindrical brake friction elements, and thereaftershaping by permanently inherently deforming said elemanently deformingsaid shoe elements to their final operative form.

3. That method of fabricating a brake friction element or the likecomprising rolling, from a no length of flat, relatively narrow sheetstock, double 7 thickness rim and web T-section stock, rolling saidstock so formed into a helix, cutting to length from said helixcylindrically shaped brake fric- 8 tion elements and thereafterpermanently deforming said friction elements to their final operativeform.

4. That method of fabricating a brake shoe friction element or the like,comprising rolling, from a length of flat, relatively narrow sheetstock, double thickness web and rim T-section stock, rolling stock soformed into a helix, cutting to length from said helix split annularbandlik friction elements, bending said elements so that their STANLEYWHITWORTH.

